NEPA Clean Energy Analysis: Progress Report

Deliverables 1 & 3

Published

January 16, 2026

Executive Summary

This report summarizes progress on analyzing NEPA (National Environmental Policy Act) compliance data for clean energy projects. We present findings from two deliverables:

  • Deliverable 1: Characterizing the clean energy project landscape by technology, lead agency, and geographic location
  • Deliverable 3: Analyzing NEPA process types (CE, EA, EIS) across energy classifications
Data Scope

Analysis covers 26,000+ clean energy projects extracted from the NEPA database, classified using energy technology tags (solar, wind, transmission, storage, geothermal, hydropower, nuclear, hydrogen, and efficiency/conservation).

Deliverable 1: Clean Energy Project Landscape

Technology Distribution

How are clean energy projects distributed across technology types?

Figure 1: Distribution of clean energy projects by technology type. Projects may have multiple technology tags.
Key Finding: Technology

Transmission and solar dominate the clean energy NEPA landscape. Transmission projects comprise the largest share, reflecting the infrastructure buildout required to connect renewable generation to load centers. Solar’s prominence aligns with its rapid deployment growth over the analysis period.

Lead Agency Analysis

Which federal agencies are leading clean energy NEPA reviews?

Table 1: Clean energy projects by lead federal department and NEPA process type
Department Categorical Exclusion Environmental Assessment Environmental Impact Statement Total
Department of Energy 20,819 476 344 21,639
Department of the Interior 4,136 233 245 4,614
Department of Agriculture 47 11 41 99
Other Independent Agencies 0 1 94 95
Department of Defense 7 2 29 38
Major Independent Agencies 0 3 30 33
General Services Administration 5 0 7 12
Department of Homeland Security 5 1 4 10
Department of Transportation 2 1 7 10
Department of Commerce 4 0 2 6
Department of Health and Human Services 0 1 4 5
Department of Housing and Urban Development 1 1 1 3
Department of State 1 0 1 2
Department of Justice 0 0 1 1
Department of Veterans Affairs 0 0 1 1
Department of the Treasury 0 0 1 1
International Assistance Programs 1 0 0 1
Legislative Branch 1 0 0 1
Total 25,029 730 812 26,571

Figure 2: Clean energy projects by lead department

Figure 3: NEPA process type composition by lead department
Key Finding: Agency

DOE dominates clean energy NEPA reviews (81% of projects), followed by Interior (17%). Notably, DOE processes the vast majority through Categorical Exclusions (96%), while Interior shows more variation across process types. This concentration suggests DOE’s loan programs and grid modernization initiatives drive most federal clean energy review activity.

Geographic Distribution

Where are clean energy projects located?

State-Level Distribution

Table 2: Top 15 states by clean energy project count
State Categorical Exclusion Environmental Impact Statement Environmental Assessment Total
South Carolina 4,143 48 23 4,214
Washington 2,165 96 62 2,323
California 1,616 186 95 1,897
Idaho 1,666 92 59 1,817
Oregon 1,320 69 31 1,420
Colorado 1,295 44 46 1,385
Nevada 955 112 27 1,094
Arizona 929 70 93 1,092
Wyoming 819 47 11 877
New Mexico 657 60 39 756
Texas 674 27 22 723
Utah 617 46 9 672
New York 591 27 12 630
Illinois 543 10 20 573
Pennsylvania 536 11 6 553
Montana 386 43 6 435

Figure 4: Clean energy projects by state. Alaska and Hawaii repositioned for display.

County-Level Distribution

Figure 5: Clean energy projects by county. Note: County data available for approximately 47% of projects.

Process Type by Location

Figure 6: Clean energy project locations by NEPA process type. Points placed at county centroids; size indicates project count.
Key Finding: Geography

Clean energy projects concentrate in the Western states and Southeast nuclear corridor. South Carolina leads (driven by Savannah River Site activity), followed by Washington, California, and Idaho. The county-level map reveals clustering around major federal facilities and high-resource renewable areas (desert Southwest for solar, Great Plains for wind).

Deliverable 3: NEPA Process Analysis

Process Types by Energy Classification

How do NEPA review processes differ across energy types (Clean, Fossil, Other)?

Figure 7: NEPA process type by energy classification

Figure 8: Composition of NEPA process types within each energy classification
Key Finding: Process Type

Clean energy projects use Categorical Exclusions at higher rates than fossil fuel projects. This likely reflects:

  1. Smaller project footprints (rooftop solar, efficiency upgrades)
  2. DOE’s programmatic CEs for loan guarantee activities
  3. Routine transmission maintenance and upgrades

Fossil projects show higher EA/EIS rates, consistent with larger environmental footprints requiring more detailed review.

Work in Progress

Completed Analysis

Deliverable Component Status
D1 Technology classification Complete
D1 Lead agency analysis Complete
D1 Geographic mapping (state, county) Complete
D3 Process type by energy classification Complete

In Progress

Generation Capacity Analysis

Data Limitation: Capacity Variables

Preliminary exploration of generation capacity fields reveals substantial missing data. We are evaluating:

  • Option A: Subset analysis using only records with capacity data (reduced sample size)
  • Option B: Imputation strategies using project type and technology proxies
  • Option C: Supplementing with external capacity databases (EIA-860)

Recommendation: We suggest discussing the tradeoffs at Thursday’s meeting to determine the preferred approach.

Timeline Analysis

NEPA review duration analysis requires:

  1. Parsing decision dates from document records
  2. Handling projects with multiple decision documents
  3. Defining appropriate start/end date conventions

Current status: Data cleaning underway; preliminary results expected next cycle.

Next Steps

  1. Finalize capacity analysis approach based on funder input
  2. Complete timeline/duration analysis for Deliverable 2
  3. Cross-deliverable synthesis — connecting technology, agency, and process type findings
  4. Validation — spot-check classifications against source documents

Report generated 2026-01-16 | NEPA Clean Energy Analysis